我這裡沒有判斷文件類型,因為png和jpeg縮放後都不會出現黑色背景,就單獨gif不行..查了下資料發現了一個完美的解決辦法,附帶有詳解
現在寫東西都喜歡封裝成類.....大家調用一下就行了..我就不說怎麼調用了 代碼如下:<?php class resize_image{ private $o_img_width;//原圖像寬度 private $o_img_height;//原圖像高度 private $n_img_width;//新圖像寬度 private $n_img_height;//新圖像高度 private $o_img_file;//原圖像文件 private $o_img_source;//原圖像資源 private $n_img_file;//新圖像資源 private $n_img_source;//新圖像資源 private $o_to_n_per=0.5;//圖像縮放比 //初始化內部變量 function __construct($oldfile,$newfile){ list($width,$height)=getimagesize($oldfile); $this->o_img_file=$oldfile; $this->o_img_width=$width; $this->o_img_height=$height; $this->n_img_file=$newfile; } //等比例縮放並且解決GIF透明色為黑色背景的問題 function get_resize_scaling_img(){ $this->n_img_width=$this->o_img_width*$this->o_to_n_per; $this->n_img_height=$this->o_img_height*$this->o_to_n_per; //等比例縮放圖片(算法) if ( $this->n_img_width && ( $this->o_img_width <$this->o_img_height)) { $this->n_img_width = ( $this->n_img_height/$this->o_img_height) * $this->o_img_width; } else { $this->n_img_height = ($this->n_img_width / $this->o_img_width) * $this->o_img_height; } $this->o_img_source=imagecreatefromgif($this->o_img_file); //創建一個等比例縮放大小的畫布 $this->n_img_source=imagecreatetruecolor($this->o_img_width,$this->n_img_height); //美化:去除黑色不透明背景 $trans_init=imagecolortransparent($this->o_img_source); //尋找透明色並且判斷是否在總顏色中 if($trans_init>=0 && $trans_init < imagecolorstotal($this->o_img_source)){ //如果在的話則搜索這個顏色的RGB色相 $trans_index=imagecolorsforindex($this->o_img_source,$trans_init); //找到之後就創建這樣一個顏色 $trans_new=imagecolorallocate($this->n_img_source,$trans_index["red"],$trans_index["green"],$trans_index["blue"]); //然後我們用這個顏色去填充新的圖像 imagefill($this->n_img_source,0,0,$trans_new); //然後我們在把填充色設置為透明 imagecolortransparent($this->n_img_source,$trans_new); } //拷貝原圖像到新畫板上 imagecopyresized($this->n_img_source,$this->o_img_source,0,0,0,0,$this->n_img_width,$this->n_img_height,$this->o_img_width,$this->o_img_height); return $this->n_img_source; } //最終銷毀資源 function __destruct(){ imagedestroy($this->o_img_source); imagedestroy($this->n_img_source); } } 說明:因為先前沒想那麼多所以聲明了很多私有的內部變量以便調用...程序看起來很笨拙啊......
